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The nation's top military officer, General Martin Dempsey, is in Israel today. The visit is being closely watched for clues that might explain how the U.S. and Israel will manage growing tensions with Iran over its nuclear program.
As NPR's Tom Bowman reports, General Dempsey is expected to deliver a firm message to the Israelis, give tough sanctions time to work and, above all, don't attack Iran.
TOM BOWMAN, BYLINE: General Dempsey's first trip to Israel comes at a particularly tense time. Iran has threatened to close the Strait of Hormuz, the key route for oil shipments. It has held naval war games. An Iranian nuclear scientist was killed by a drive-by assassin. Iran blames Israel and the United States.
JON ALTERMAN: This is getting very dangerous.
BOWMAN: Jon Alterman is a former State Department official who runs the Middle East Program at the Center for Strategic and International Studies.
ALTERMAN: All of the senior people I know in the U.S. government are starting to lose sleep over where this all might go.
BOWMAN: Where this all might go. The greatest concern for U.S. officials is an Israeli attack on Iran's nuclear facilities, which Iran insists are only for peaceful purposes. An Israeli attack, said one Pentagon official, could lead to Iranian agents striking U.S. military and diplomatic personnel throughout the Middle East.
Some U.S. officials believe that an Israeli attack is more likely now because Iran is moving forward on its nuclear program, even hiding portions of it deep inside a mountain, and because the U.S. military has left Iraq. Israeli war planes could fly directly across Iraq, even without Iraq's permission, to bomb Iranian nuclear sites.
Israeli Defense Minister Ehud Barak has downplayed any imminent attack. Here he is this week in an interview with Israeli army radio.
EHUD BARAK: (Through Translator) We haven't made any decision to do this. The entire thing is very far off.
BOWMAN: Maybe far off, but still possible. Gawdat Bahgat is a Middle East expert at National Defense University. He says Israel will mount an attack if it sees Iran's nuclear program progressing past a certain point.
GAWDAT BAHGAT: I believe Israel has its own red lines, and if Iran crosses these red lines, Israel will attack.
BOWMAN: The sense among experts is that Israeli officials are debating where that red line is. There is disagreement about what milestones would warrant air strikes by Israel. Again, Jon Alterman, the former State Department official.
ALTERMAN: I don't think the Israelis know what their intention is. I think they genuinely haven't made a decision. I think when they do make a decision it's not going to be a decision they're going to share widely.
BOWMAN: Would they have to tell the U.S., though, do you think?
ALTERMAN: My guess is the Israelis would have to give the United States at least some number of minutes warning, but probably not much more than that.
BOWMAN: Alterman says, at least for the time being, Israel will wait and see if tougher sanctions work. American officials, for their part, are continuing to push for such non-military pressure on Iran's nuclear program.
Here's Defense Secretary Leon Panetta on CBS's "Face the Nation" earlier this month.
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BOWMAN: Still, even Panetta says that no option is off the table, even a military one to prevent Iran from building a nuclear bomb. On the same program, General Dempsey was asked if the U.S. could destroy Iran's nuclear program.
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BOWMAN: Dempsey would only say that his job is to plan for all military options, but the case General Dempsey is making in Israel is to hold off on any military action.
Tom Bowman, NPR News, Washington.